Question 20

They're grammar and mathematics books.

This sentence correctly uses "they're," which is a contraction of "they are," to describe the books in question. It adheres to proper grammatical structure and conveys a clear meaning.

A) The two books are over their.

This option is incorrect because "their" is a possessive pronoun that does not fit the context of the sentence. The phrase lacks clarity and does not convey a complete thought.

B) There my favorite textbooks.

This choice is incorrect as it uses "there," which refers to a place, instead of "they're," which is the contraction needed to indicate that those books are favorites. The sentence is grammatically flawed and lacks coherence.

C) Their very heavy and have graphic covers.

This option is incorrect because it mistakenly uses "their" instead of "they're." The intended meaning is to describe the books, which requires the contraction for "they are." Thus, this sentence fails to be grammatically correct.

D) They're grammar and mathematics books.

This sentence is grammatically correct as it uses "they're," the contraction for "they are," appropriately to identify the subjects, which are the grammar and mathematics books. It presents a clear and coherent statement.

Conclusion

The sentence "They're grammar and mathematics books." is the only option that correctly utilizes the contraction "they're" to convey the intended meaning. All other choices either misuse pronouns or fail to form a complete thought, demonstrating a lack of grammatical accuracy. Hence, option D stands out as the only correct answer.